Stack for mixed reactant fuel cell and mixed reactant fuel cell system including the same

Abstract

A stack for a mixed oxidant fuel cell and a mixed oxidant fuel cell system including the stack. The stack includes at least one membrane-electrode assembly that includes a polymer electrolyte membrane, an anode and a cathode disposed on opposite sides of the polymer electrolyte membrane, and an electrode substrate disposed on at least one of the anode or the cathode; and an oxidant supply path and a fuel supply path that penetrate the membrane-electrode assembly. The oxidant supply path has both ends open, and the fuel supply path has one end open and the other end closed. The stack of the present invention can improve fuel cell efficiency by smoothly supplying a fuel and an oxidant. Particularly, since the stack is configured to supply the fuel and the oxidant without using a pump, it can make a fuel cell small and light.

1. A stack for a mixed reactant fuel cell, comprising:
 at least one membrane-electrode assembly comprising a polymer electrolyte membrane, an anode and a cathode disposed on opposite sides of the polymer electrolyte membrane, and an electrode substrate disposed on at least one of the anode or the cathode; and 
 a plurality of oxidant supply paths extending through the at least one membrane-electrode assembly in a first direction and a plurality of fuel supply paths alternating with the oxidant supply paths, the oxidant supply paths and the fuel supply paths penetrating the at least one membrane-electrode assembly, 
 wherein each oxidant supply path of the plurality of oxidant supply paths has openings at opposite ends of the oxidant supply path in the first direction, each of the openings being configured to supply oxidant to the at least one membrane-electrode assembly, and each fuel supply path of the plurality of fuel supply paths has one end open and the other end closed. 
 
     
     
       2. The stack of  claim 1 , wherein an area of a cross-section of at least one oxidant supply path perpendicular to a path propagation direction ranges from 1 mm 2  to 20 mm 2 . 
     
     
       3. The stack of  claim 2 , wherein the area of the cross-section of the at least one oxidant supply path perpendicular to the path propagation direction ranges from 1.5 mm 2  to 3 mm 2 . 
     
     
       4. The stack of  claim 1 , wherein an area of a cross-section of at least one fuel supply path perpendicular to a path propagation direction ranges from 1 mm 2  to 5 mm 2 . 
     
     
       5. The stack of  claim 4 , wherein the area of the cross-section of the at least one fuel supply path perpendicular to the path propagation direction ranges from 1 mm 2  to 2 mm 2 . 
     
     
       6. The stack of  claim 1 , wherein at least one fuel supply path occupies 10% to 20% of the at least one membrane-electrode assembly. 
     
     
       7. The stack of  claim 1 , wherein the polymer electrolyte membrane, the anode and the cathode have pores for distributing fuel and the oxidant in the at least one membrane-electrode assembly by diffusion. 
     
     
       8. A mixed reactant fuel cell system, comprising:
 a stack comprising at least one membrane-electrode assembly comprising a polymer electrolyte membrane, an anode and a cathode disposed on opposite sides of the polymer electrolyte membrane, and an electrode substrate disposed on at least one of the anode or the cathode; 
 a plurality of oxidant supply paths extending through the at least one membrane-electrode assembly in a first direction and a plurality of fuel supply paths alternating with the oxidant supply paths, the oxidant supply paths and the fuel supply paths penetrating the at least one membrane-electrode assembly, wherein each oxidant supply path of the plurality of oxidant supply paths has openings at opposite ends of the oxidant supply path in the first direction, each of the openings being configured to supply oxidant to the at least one membrane-electrode assembly, and each fuel supply path of the plurality of fuel supply paths has one end open and the other end closed; and 
 a fuel supplier for supplying fuel to the stack through the open end of each fuel supply path. 
 
     
     
       9. The mixed reactant fuel cell system of  claim 8 , wherein an area of a cross-section of at least one oxidant supply path perpendicular to a path propagation direction ranges from 1 mm 2  to 20 mm 2 . 
     
     
       10. The mixed reactant fuel cell system of  claim 9 , wherein the area of the cross-section of the at least one oxidant supply path perpendicular to the path propagation direction ranges from 1.5 mm 2  to 3 mm 2 . 
     
     
       11. The mixed reactant fuel cell system of  claim 8 , wherein an area of a cross-section of at least one fuel supply path perpendicular to a path propagation direction ranges from 1 mm 2  to 5 mm 2 . 
     
     
       12. The mixed reactant fuel cell system of  claim 11 , wherein the area of the cross-section of the at least one fuel supply path perpendicular to the path propagation direction ranges from 1 mm 2  to 2 mm 2 . 
     
     
       13. The mixed reactant fuel cell system of  claim 8 , wherein at least one fuel supply path occupies 10% to 20% of the at least one membrane-electrode assembly. 
     
     
       14. The mixed reactant fuel cell system of  claim 8 , further comprising a fuel suction part for supplying the fuel from the fuel supplier to the stack. 
     
     
       15. The mixed reactant fuel cell system of  claim 8 , wherein the mixed reactant fuel cell system comprises a direct oxidation fuel cell. 
     
     
       16. The mixed reactant fuel cell system of  claim 8 , wherein the polymer electrolyte membrane, the anode and the cathode have pores for distributing the fuel and the oxidant in the at least one membrane-electrode assembly by diffusion.